Holding device



y 11, 1965 D. A. BOYLAN 7 3,182,687

HOLDING DEVICE Filed May 21, 1962 Fig.|.

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67 INVEN TOR 6/ Donald A. Boylon ATTOI'RNEY United States Patent M3,182,687 HOLDING DEVICE Donald A. Boylan, Township, Steuben County,N.Y., assignor to Westinghouse Electric Corporation, East Pittsburgh,Pa., a corporation of Pennsylvania Filed May 21, 1962, Ser. No. 196,1195 Claims. (Cl. 140-715) The present invention relates to devicesforwinding grid electrodes for use in electron tubes and, moreparticularly, to a holding means adaptable to standard grid machines forslidably retaining the frame strip of a frame type grid at a point nearwhich the grid is being wound.

In the winding of conventional grids, that is, notched and peened gridshaving only side rods with grid laterals wound thereon, the side rodsslide individually through holes or grooves in a mandrel which is heldby the rotating lathe head or spindle. In the case of frame grids,however, this method will not work as the presence of cross membersbetween the side support rods prevents the side rods from being heldindividually.

The prior art method of winding a strip of frame grids employed atechnique whereby the grid strip was clamped at its extreme ends in acarriage, and the strip and its carriage were traversed past the windingpoint. Alternatively, the winding point was made to traverse the lengthof the grid strip. By either technique, the strip was unsupported in itscenter portion when lateral wire was being wound on this portion of thestrip. Therefore, the strip length was largely limited by the mechanicalstrength of the strip in its ability to resist the bending. force of thelateral wire tension rather than by machine or other considerations.

In a copending application assigned to the assignee of the presentinvention, titled Frame Grid Holding Apparatus by William H. Simmonds,Serial No. 196,123, filed May 21, 1962, there is described a guide forslidably maintaining a grid strip of the frame type. The guide providesbriefly, that the grid strip is maintained between two adjustable jawswhich are mounted on a suitable base member. While this guide is muchmore satisfactory than the prior art, there is a possibility that theuse of this guide may upon occasion, permit a certain amount ofvibration of the grid strip in the jaw members. This vibration is due tothe fact that the distance between the jaws must be set to the maximumdimensions of the strip (plus clearance) and that a slight reduction inthese dimensions would result in the grid strip being somewhat looselyheld at the reduced dimension points.

. It is, therefore, an object of this invention to provide an improvedmeans for adapting standard grid winding machines to the winding offrame type grids.

Another object is to provide an improved holding device for use in theWinding of frame grids.

A further object is to provide an improved means for securely holding aframe grid strip in a slidable manner.

Briefly, the present invention provides a holding means for slidablyretaining a frame grid strip. The holding device may be mounted on therotating spindle or head of any convenient grid winding machine or itmay be maintained stationary. In either case, the grid strip is grippedat one end and drawn through'the holding device Which includes resilientmeans acting upon the grid strip in planes mutually transverse to eachother to'maintain the grid strip in firm contact with two referencesurfaces. The winding station or point maybe positioned closely adjacentthe holding device and thus thedevice serves to sup port the stripagainst the bending occasioned by the winding of the grid laterals andto reduce this bending to a negligible amount. Thus the total length ofgrid strip 3,182,687 Patented May 11, 1965 which may be utilized islimited largely by machine design and handling considerations.

Further objects and advantages of the invention will become apparent asthe following description proceeds and features of novelty whichcharacterize the invention will be pointed out in particularity in theclaims annexed to and forming a part of this specification.

For a better understanding of the invention, reference may be had to theaccompanying drawings, in which:

FIGURE 1 is a front plane view of a holding device in accordance withthe present invention;

FIG. 2 is a side elevational view of the device of FIG. 1; and

FIG. 3 is a side elevational view of one of the resilient or springmembers of the device of FIG. 1.

Referring now to FIGS. 1 to 3, there is shown a device for holding aframe grid strip in accordance with the present invention. Theembodiment shown is one of convenient design which is adapted formounting on the rotating head or spindle of a conventional grid makingmachine, for example a lathe such as that described in United StatesPatent No. 2,441,228, issued May 11, 1948.

The device comprises a base member 12 which serves as a suitableplatform to which a support member 30 is attached. The base 12 ispreferably cylindrical in shape, of a suitable material such as steel,and is provided with a rearwardly extending portion 16 which may bepressfitted into a hollow rotating spindle of the grid winding machine.The base 12 is also provided with a centrally extending bore 20 topermit the longitudinal passage of the frame grid strip therethrough.

In FIG. 2, there is shown a frame grid strip 22 of the type for whichthe present invention is designed. The end view of this strip 22 may beseen in FIG. 1. The strip 22 comprises a pair of support or side rods 24which are held in a spaced relationship by a plurality of cross bars 26.The cross bars 26 are affixed to the side rods 24 by a suitable meanssuch as welding. The strip 22 is prefabricated prior to the winding ofthe grid laterals in a manner well known in the art.

A suitable recess 28 is provided in the top surface of the base member12. A support member 30 is disposed within the recess and is afiixed tothe base member by a suitable means, for example a pair of bolts 32which extend longitudinally through the support member 30 and aresecured in the base member 12. One side of the support member 30 isprovided with an offset portion indicated generally at 40 and the member30 is placed so that the olfset portion 40 is positioned over thecentrally extending bore 20 of the base member 12. The offset portion 40provides a first fixed surface 42 and a second fixed surface 44 whichare positioned in planes substantially perpendicular to one another andextend longitudinally the length of the member 30. As has been stated,the offset portion 40 is positioned substantially over the centrallyextending bore 20 and the fixed surfaces 42 and 44 serve as fixedreferences against which the grid strip 22 is maintained in a slidablefashion.

The fixed surface 42 provides the fixed reference surface against whichthe cross members 26 of one side of side of the side rods 24 do nottouch the fixed surface 44..

Thus, in the preferred embodiment, the fixed surface 44 has a widthsmaller than the diameter of the side rods 24 and this surface 44 is incontact with substantially only one side rod 24 of the grid strip 22.

The grid strip 22 is held firmly against the fixed surfaces 42 and 44 bymeans of two resilient or spring members d and 6% which are secured tothe support member 30. The first resilient member 50 acts upon the upperside rod- 24 of the frame grid strip 22 to maintain the strip againstthe fixed surface 44-. The resilient means 559 is preferably comprisedof a spring wire member having one end 52 thereof secured to the supportmember 3d. The other end 56 of the wire member St? is of substantiallyU-shaped configuration and is positioned about a stud member 58 which isaifixed to the support 30 in a manner to limitthe movement of the freeend 56 of the member 54). A fulcrum 54 is positioned intermediate theends 56, 52 of the member Sti in a manner to bias the member 50 in adownwardly direction. The member 54) has a diameter preferably notexceeding that of the side rods 24, and its action is substantially onlyon upper side rod 24 to maintain the lower side rod 24 in contact withthe fixed surface 44.

The second resilient or spring means 60 may best be seen in FIGS. 2 and3. The resilient means as is comprised of a main portion 62 and two legportions 64 and 66. The member 60 is provided with one or more holes 67in its lower portion and is secured to the support member 3% by means ofsuitable fastening means, for example bolts 68. The leg 64 is bent fromthe plane of the rest of the member 6th at as to provide that the outerportion 65 of the leg 64 lies in a plane substantially parallel butslightly displaced from the plane of the body portion 62 of the member60. The leg 64 is preferably slightly smaller in width than the width ofthe grid strip 22 and also has a length. sufiicient to span, at any onetime, a plurality of cross bars 26 of the grid strip 22. The member 60is supported by the support member 36 and is positioned so that thedistance between the fixed surface 42 and the'leg portion 65 is slightlyless than the thickness of'the cross bars 26 and the side rods 24combined. In this manner, the resilient member as serves to maintain thegrid strip 22 firmly against the fixed surface 42.

In the winding operation, one end of the grid strip 22 is attached tosuitable means, such as a draw bar, which provides the strip 22 withboth rotary motion about and linear motion along its longitudinal axis.The lathe spindle, andhence the holding device of the present invention,which issecured to the spindle, is rotated at a speed synchronous withthat of the draw bar. A suitable means 7% for directing the grid lateralwire 72 onto the strip 22 is positioned at a point near to the free endof the support member 30. Thus, as the grid laterals are drawn on to therotating strip 22, the holding device of this invention provides therequisite support to prevent the bending of the strip 22.

In the preferred embodiment, each of the resilient .means 56 and60'exert approximately one-half pound of pressure against the grid strip22. It is thus readily seen that thedevice thus described permits thestrip 22 to be slidably maintained in a device and yet, through theaction of the resilient members 50 and 66 holding the grid strip 22against the'fixed reference surfaces 42 and 44, any vibration of thestrip 22 within the holding device is eliminated.

Although the invention has thus far been explained as being mounted onthe rotary spindle. of a lathe or other suitable grid winding machine,it has equal application as a stationary member through which a gridstrip 22 is drawn. In this latter embodiment, the strip 22 is providedbefore, the winding should take place at a point which is. in closeproximity to the free end of the support member 30.

While there have been shown and describedwhat are at present consideredto be the preferred embodiments of the invention, modifications theretowill readily occur to those skilled in the art. It is not desired,therefore, that the invention be limited to the specific arrangementshown and described and it is intended to cover in the appended claimsall such modifications as fall within the true spirit and scope of theinvention.

I claim as my invention:

1. In a grid winding machine, a holding device for slidably retaining aframe grid strip having first and second side rods and a plurality ofcross bars affixed to and maintaining said side rods in a spacedrelationship comprising a support member having first and second fixedsurfaces lying in planes substantially perpendicular to each other,first resilient means acting upon said first side rod to maintain saidsecond side rod in slidable contact with said first fixed surface, andsecond resilient means acting simultaneously upon a plurality of saidcross bars to maintain said grid strip in slidable contact with saidsecond fixed surface. 7

2. In a grid winding machine, a holding device for slidably retaining aframe grid strip having first and second side rods and a plurality ofcross bars affixed to and maintaining said side rods in a spacedrelationhsip comprising a support member, first and second fixedsurfaces on said support member against which said grid strip isslidably held, said fixed surfaces lying in planes substantiallyperpendicular to one another, recess means extending between said fixedsurfaces whereby said surfaces do not meet, first resilient means actingupon said first side rod to maintain said second-side rod in slidablecontact with said first fixed surface, and second resilient means actingsimultaneously upon a plurality of said cross bars whereby said gridstrip is also maintained in slidable contact with said second fixedsurface.

3. In a grid winding machine, a holding device for slidably retaining aframe grid strip having first and second side rods and a plurality ofcross bars afiixed to and maintaining said side rods in a spacedrelationship comprising a support member, first and second fixedsurfaces on said support member against which said grid strip isslidably held, said fixed surfaces lying in planes substantiallyperpendicular to each other, recess means extending between said fixedsurfaces whereby said surfaces do not contact one anoth'er, said firstfixed surface having a dimension transverse to the length of said gridstrip not exceeding the diameter of said side rods, first meansresiliently biased to act upon said first side rod to maintain saidsecond side rod in slidable contact with said first fixed surface, andsecond means resiliently biased to act upon a plurality of said crossbars to maintain said grid strip in slidable contact with said secondfixed surface.

' 4. In a grid winding machine, a holding device for slidably retaininga frame grid having first and second side rods and cross bars affixed toand maintaining said side rods in a spaced relationship comprising asupport member, first and second fixed surfaces on said support memberagainst which said grid strip is slidably held, said fixed surfaceslyingin planes substantially perpendicular to each other, recess meansextending between said fixed surfaces whereby said surfaces do not meet,said first fixed surface having a dimension transverse to the length ofsaid grid strip which is less than the diameter of said side rods, firstresilient means secured to said support member, means for biasing saidfirst resilientmeans in a direction whereby said first resilient meansacts upon said first side rod to maintain said second side rod inslidable contact with said first fixed surface, means for limiting themovement of said first resilient means, and second resilient meansbiased to act upon a plurality of said cross bars for maintaining saidgridfstrip in slidable; contact with said second fixed surface.

5. In a grid winding machine, a holding device for slidably retaining aframe grid strip having first and second side rods and'a pluralityofcross bars aflixed'to and maintaining said side rods in a spacedrelationship comprising a support member, first and second fixedsurfaces on said support member against which said grid strip isslidably held, said fixed surfaces lying on planes substantiallyperpendicular to one another, recess means extending between said fixedsurfaces whereby said surfaces do not meet, first resilient means actingupon said first side rod to maintain said second side rod in slidablecontact with said first fixed surface, and second resilient meansperpendicular to said second fixed surface to maintain said grid stripin slidable contact with said second fixed surface.

References Cited by the Examiner UNITED STATES PATENTS 2,973,197 2/61Algott et a1 269-2S4 3,028,170 4/62 Norris 269-265 CHARLES W. LANHAM,Primary Examiner.

acting upon said grid strip in a direction substantially s WILLIAM F.PURDY, Examiner.

1. IN A GRID WINDING MACHINE, A HOLDING DEVICE FOR SLIDABLY RETAINING AFRAME GRID STRIP HAVING FIRST AND SECOND SIDE RODS AND A PLURALITY OFCROSS BARS AFFIXED TO AND MAINTAINING SAID SIDE RODS IN A SPACEDRELATIONSHIP COMPRISING A SUPPORT MEMBER HAVING FIRST AND SECOND FIXEDSURFACES LYING IN PLANES SUBSTANTIALLY PERPENDICULAR TO EACH OTHER,FIRST RESILIENT MEANS ACTING UPON SAID FIRST SIDE ROD TO MAINTAIN SAIDSECOND SIDE ROD IN SLIDABLE CONTACT WITH SAID FIRST FIXED SURFACE, ANDSECOND RESILIENT MEANS ACTING SIMULTANEOUSLY UPON A PLURALITY OF SAIDCROSS BARS TO MAINTAIN SAID GRID STRIP IN SLIDABLE CONTACT WITH SAIDSECOND FIXED SURFACE.